Metrology methods and targets are provided for reducing or eliminating a difference between a device pattern position and a target pattern position while maintaining target printability, process compatibility and optical contrast—in both imaging and scatterometry metrology. Pattern placement discrepancies may be reduced by using sub-resolved assist features in the mask design which have a same periodicity (fine pitch) as the periodic structure and/or by calibrating the measurement results using PPE (pattern placement error) correction factors derived by applying learning procedures to specific calibration terms, in measurements and/or simulations. Metrology targets are disclosed with multiple periodic structures at the same layer (in addition to regular target structures), e.g., in one or two layers, which are used to calibrate and remove PPE, especially when related to asymmetric effects such as scanner aberrations, off-axis illumination and other error sources.

Metrology methods and targets are provided for reducing or eliminating a difference between a device pattern position and a target pattern position while maintaining target printability, process compatibility and optical contrast—in both imaging and scatterometry metrology. Pattern placement discrepancies may be reduced by using sub-resolved assist features in the mask design which have a same periodicity (fine pitch) as the periodic structure and/or by calibrating the measurement results using PPE (pattern placement error) correction factors derived by applying learning procedures to specific calibration terms, in measurements and/or simulations. Metrology targets are disclosed with multiple periodic structures at the same layer (in addition to regular target structures), e.g., in one or two layers, which are used to calibrate and remove PPE, especially when related to asymmetric effects such as scanner aberrations, off-axis illumination and other error sources.

Method (and apparatus) for producing a 3D target structure in lithographic material. Focus region of a laser writing beam travels through a scanning manifold through the lithographic material. In the focus region of the laser writing beam, an exposure dose is irradiated into the lithographic material, and a structure region is locally defined. At least one exposure data set which represents a local exposure dose for the scan manifold as a function of location is determined. A structure which approximates the target structure is defined based on at least one exposure data set. This structure is analyzed and at least one analysis data set which represents the analyzed structure is determined. Deviation data set which represents deviations of the already defined structure from the target structure is determined. At least one correction exposure data set is determined. Correction structure based on the at least one correction exposure data set is defined.

Method (and apparatus) for producing a 3D target structure in lithographic material. Focus region of a laser writing beam travels through a scanning manifold through the lithographic material. In the focus region of the laser writing beam, an exposure dose is irradiated into the lithographic material, and a structure region is locally defined. At least one exposure data set which represents a local exposure dose for the scan manifold as a function of location is determined. A structure which approximates the target structure is defined based on at least one exposure data set. This structure is analyzed and at least one analysis data set which represents the analyzed structure is determined. Deviation data set which represents deviations of the already defined structure from the target structure is determined. At least one correction exposure data set is determined. Correction structure based on the at least one correction exposure data set is defined.

The inventive concept provides a mask treating apparatus. The mask treating apparatus includes a support unit configured to support and rotate a mask, the mask having a first pattern within a plurality of cells thereof and a second pattern outside regions of the plurality of cells; and a heating unit having a laser irradiator for irradiating a laser light to a specific region of the mask supported on the support unit, and a controller configured to control the support unit and the heating unit, and wherein the support unit includes: a support part for supporting the mask; and a moving stage part configured to move a position of the support part, and wherein the controller controls the moving stage part so a position of the mask supported on the support part is changed so the second pattern is positioned at the specific region.

A method for manufacturing a semiconductor includes: receiving a photomask substrate including a shielding layer; defining a chip region and a peripheral region adjacent to the chip region; forming a design pattern in the chip region; forming a reference pattern by emitting one first radiation shot and a beta pattern by emitting a plurality of second radiation shots in the peripheral region, wherein a pixel size of the first radiation shot is greater than a pixel size of the second radiation shot; comparing a reference roughness of a boundary of the reference pattern and a beta roughness of a boundary of the beta pattern; transferring the design pattern to the shielding layer if a difference between the reference roughness and the beta roughness is within a tolerance; and transferring the design pattern of the photomask to a semiconductor substrate.

A method for manufacturing a semiconductor includes: receiving a photomask substrate including a shielding layer; defining a chip region and a peripheral region adjacent to the chip region; forming a design pattern in the chip region; forming a reference pattern by emitting one first radiation shot and a beta pattern by emitting a plurality of second radiation shots in the peripheral region, wherein a pixel size of the first radiation shot is greater than a pixel size of the second radiation shot; comparing a reference roughness of a boundary of the reference pattern and a beta roughness of a boundary of the beta pattern; transferring the design pattern to the shielding layer if a difference between the reference roughness and the beta roughness is within a tolerance; and transferring the design pattern of the photomask to a semiconductor substrate.

An operating method includes: placing a first mask, a second mask, a third mask and a fourth mask on a rotating base, in which each of the first, second, third and fourth masks has a first exposure unit, a second exposure unit, a third exposure unit and a fourth exposure unit; overlaying the first, second, third and fourth masks such that the first exposure unit of the first mask, the second exposure unit of the second mask, the third exposure unit of the third mask and the fourth exposure unit of the fourth mask are arranged adjacently to form an exposure area; simulating a first coordinate information according to the exposure area by an image simulation unit; scanning the exposure area, by a scanning electron microscope (SEM), to obtain a second coordinate information; and comparing the first coordinate information with the second coordinate information.

An operating method includes: placing a first mask, a second mask, a third mask and a fourth mask on a rotating base, in which each of the first, second, third and fourth masks has a first exposure unit, a second exposure unit, a third exposure unit and a fourth exposure unit; overlaying the first, second, third and fourth masks such that the first exposure unit of the first mask, the second exposure unit of the second mask, the third exposure unit of the third mask and the fourth exposure unit of the fourth mask are arranged adjacently to form an exposure area; simulating a first coordinate information according to the exposure area by an image simulation unit; scanning the exposure area, by a scanning electron microscope (SEM), to obtain a second coordinate information; and comparing the first coordinate information with the second coordinate information.

A method of performing a lithography process includes providing a test pattern. The test pattern includes a first set of lines arranged at a first pitch, a second set of lines arranged at the first pitch, and further includes at least one reference line between the first set of lines and the second set of lines. The test pattern is exposed with a radiation source providing an asymmetric, monopole illumination profile to form a test pattern structure on a substrate. The test pattern structure is then measured and a measured distance correlated to an offset of a lithography parameter. A lithography process is adjusted based on the offset of the lithography parameter.